Sectional steam-boiler



Patented July 1, 1890.

N. W. PRATT. SBGTIONAL' STEAM BOILER.

(No Model.)

me nonms varen.; co., PHoToALITHo., WASHINGTON, n. c,

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NAT W'. PRATT, OF BROOKLYN, NEV YORK.

SECTIONAL STEAM-BOILER.

SPECIFICATION forming'part of Letters Patent No. 431,480, dated July 1, 1890.

Application filed March 5, 1889. Serial No. 301,951. (No model.)

have their several opposite and adjacent ends" terminated by suitable headers, through which they communicate usually in vertical order with the said drums.

My invention especially relates to a construction of water-tube boilers wherein a plurality of longitudinal steam-drums are employed in cross series-that is to say, a series that succeed one another horizontally as viewed in cross-section of the boiler-each drum being connected into a common system by a suitable cross-drum or other transverse' connection communicating to them all.

The object of my invention is to dispense with the use of an intermediate transverse connecting-box such as usually employed where it is desired to connect a plurality of water-tube headers with a lesser plurality of steam-drums; and my said invention consists in certain novel features of construction, wherein the boiler is made up of separable sections divided by vertical planes, each section comprising a complete generator in itself-namel y, two vertical series of inclined water-tubes, independent headers uniting them, and a steanrdrum common to the independent headers. The transportation and the operation of setting up the boiler are thereby facilitated to a great extent, especially where the appliances to be obtained are limited.

Referring' to the accompanying drawings, Figure l is a general elevation of the vertical headers at the front of the water-tube boiler, showing the relative position of the steamdrums back of them at the top; Fig. 2, an enlarged front elevation of the steam-drum and connected parts, showing in detail certain features of construction; Fig. 3, a side elevation of Fig. 2; Fig. et, an enlarged front elevation showing in detail certain features of modified construction; Fig. 5, a side elevation of Fig. 4, and Fig. 6 a plan view of a further modification.

The forms of the headers A shown in Fig.

1 are adapted to connect water-tubes that are staggered with vertical relation to each other, as common in water-tube boilers, and to this purpose the said headers A are made serpentine in form to receive such tubes in single vertical series-that is to say, whereby one tubefrom each horizontal cross series is placed in communication with an individual header. The invention is, however, applicable to any other form of vertical header than that illustrated, provided they are qualified by a transverse series of upper terminations, as B in the several figures.

. It has been usual heretofore to terminate the headers at a point beneath the line of the drums, in order to permit the interposition of the connecting-box before referred to. The novel feature herein relating to the headers A consists in an upward prolongation of the headers themselves, whereby they terminate at a point opposite or above the line of the drums O, as clearly illustrated, and whereby portions of their surface come opposite the ends of the drums and perpendicular to the axes thereof.

The drums C are terminated by heads D, secured Within the margins of their ends in any well-known or suitable manner. The heads shown are flanged outwardlyand welded into the margins of the surrounding shell in the instances of all the igures.

The drums O extend to a point proximate to but not quite touching the adjacent surfaces of the headers, and the connection between the interiors of said drums and the interiors of said headers is established by the nipples E, that are expanded by means of a suitable expanding-tool into the adjacent apertures through the heads D and extensions B opposite to them. Each drum is preferably connected with two of the headers, but may, within the scope of the invention, be connected with anynumber of headers other than two, according to the proportionate size of the drum to the headers and the relative positions of the same. Each header is connected with the drum-head by a single nipple; but the number of nipples employed may be also va- IOO ried-as, for instance, two from each header connecting with the drum-head, the one nipple located above the other.

A feature of the invention illustrated in Figs. 2, 3, and 6 is that relating to the position of the nipples With relation to the line of thrust by which the parts tend to separate under pressure, and whereby I am enabled to connect a greater plurality than two of the headers to the drum. The head D is in this instance of convex form externally, and the nipples E, intersecting said head D at points proximate to the sides thereof and perpendicular to the surfaces of the metal at the point of intersection, consequently diverge with reference to the axis of the drum, so as to extend apart sufficiently at their outer ends to include the desired number of headers. ThenipplesEintersect the metal of the headers A at opposite angles in this instance, and, the headers being rigidly secured together serially as a Whole when the structure is set up, the divergent intersection of the nipples therein and into the drum-head also affords a purchase with reference to the direction of the longitudinal axis of the drum, rendering the joints secure against endwise separation.

A feature of the invention illustrated in Figs. 4 and 5 is that in which the drum is partly terminated by the iiattening and reduction of that portion approaching its end, and the remainder of the termination formed by the insertion of an oblong` head D at its ilattened end. A reduced surface of the drumhead, against which internal pressure is exerted, is thereby obtained, and the drum-head may thereby be made fiat, such a form of construction affordingample surface through which to connect the nipples singly to the headers, as shown. In this illustration Ihave shown the nipples E as having their axes parallel With each other-an advantage incident to which is that of expanding the nipples into a seat through which they intersect squarely*that is to say, at perfect right angles to the plane of the metal in which thel aperture is made-whereby the action of the expanding-tool is rendered perfect, especially should the metal of the header be of small thickness.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-

l. A sectional Water-tube boiler, each unit of which includes two adjacent vertical series of inclined Water-tubes, separate adjacent vertical headers connecting the same, and a horizontal steam and Water drum nippled at its respective ends to the upper ends of adjacent pairs of said headers opposite said ends.

2. In a Water-tube boiler, the combination of the vertical headers and a steam and Water drum opposite the upper ends thereof iiattened and broadened at its adjacent end to receive the horizontal series of connectingnipples of the headers.

3. In a water-tube boiler, the combination of water-tubes arranged as described, headers connecting them in single vertical series, and a horizontal series of steam and water drums having flattened and broadened ends opposite the upper ends of the headers independently connected to successivev pairs thereof.

NAT W'. PRATT.

Witnesses:

C. W. FoRBEs, HENRY F. PARKER. 

